Synopsis: Zooming in on Failures

A near-infrared microscopy technique can detect defects in electronic devices with a resolution better than the diffraction limit of light.
Synopsis figure
K. Agarwal et al., Phys. Rev. X (2015)

As integrated circuits are increasingly miniaturized, it becomes crucial to develop nondestructive ways to detect the presence of defects with sufficient spatial resolution. According to semiconductor industry requirements, a resolution of 100 nanometers (nm) is necessary for characterizing state-of-the-art flash memories and next-generation circuits. A number of theoretical studies indicated that “super-resolution” microscopy techniques could be used to localize defects with the required resolution and in a noninvasive way. Now, a team of researchers led by Xudong Chen at the National University of Singapore has used a near-infrared microscope to experimentally resolve 100-nm features buried in integrated silicon circuits.

Localizing defects within a silicon substrate requires using near-infrared light because silicon is opaque to optical and ultraviolet radiation. However, the Rayleigh resolution limit of near-infrared light is several times too large to detect 100-nm features. Chen and his team overcame this limitation by illuminating the defects using near-infrared light shone through a spherical silicon lens. The lens, placed flush against the substrate, enabled near-field image acquisition with a resolution increased by roughly the refractive index of silicon (3.4). The light reflected by the sample was collected by a photodetector after passing through a pinhole, whose size was optimized to prevent certain distortions of the image collected by the detector. Chen and his collaborators suggest that the resolving power of their microscope can be augmented with other types of filters to yield even higher resolutions: A resolution of 75 nm will be necessary for industrial needs by 2026, according to predictions.

This research is published in Physical Review X.

–Katherine Kornei


Features

More Features »

Announcements

More Announcements »

Subject Areas

OpticsElectronicsIndustrial Physics

Previous Synopsis

Next Synopsis

Quantum Information

Nanofiber Optical Memory

Read More »

Related Articles

Viewpoint: Resonant Ionization Spectroscopy Technique Becomes Tabletop  Friendly
Atomic and Molecular Physics

Viewpoint: Resonant Ionization Spectroscopy Technique Becomes Tabletop Friendly

A modified version of a spectroscopic technique used at large-scale radioactive-ion-beam facilities could be used in tabletop experiments. Read More »

Focus: Nobel Prize—Lasers as Tools
Optics

Focus: Nobel Prize—Lasers as Tools

The 2018 Nobel Prize in Physics goes to innovators in laser physics responsible for optical tweezers and high-intensity, ultrashort optical pulses. Read More »

Synopsis: Ghost Imaging with Electrons
Optics

Synopsis: Ghost Imaging with Electrons

Ghost imaging—a sensitive imaging technique previously demonstrated with visible and x-ray light—has been extended to electrons. Read More »

More Articles